If you have changed the cover art for your podcast on Acast and it is not yet appearing in Apple Podcasts, the following steps can help troubleshoot the cause.
Have you published the changes? Use this guide to identify if there are any un-published changes.
The new cover art may not meet Apple Podcasts' minimum image requirements. Use this guide to ensure the cover art you've uploaded meets the Apple Podcasts specification.
Apple Podcasts warn they might not update cover art for a show if the filename is the same as the previous image. Ensure the filename you've given for the new artwork is different (e.g. newcoverart.jpg instead of coverart.jpg) and re-upload if necessary. More information can be found here.
Your artwork should be updated automatically within 24-48 hours. If your artwork is not updated by then, we suggest reaching out to Apple for assistance.
NOTE: This applies only to Show covers. Apple does not support individual episode artwork. Here's some more information about how different apps handle your podcast show notes and cover art.